Treatment of storage-battery plates.



, employed in the process.

mar 'sas aras one.

CAMPBELL C. CARPENTER, OF BUFFALO, NEW YGRK, ASSIGNOR, BY MESNE ASSKG'N- MENTS, T0 GUABANTY TRUST COMPANY OF NEW YORK, TRUSTEE, A CORPORATION OF NEW YORK.

TREATMENT OF STORAGE-BATTERY PLATES.

No Drawing.

is known as the active material and the process applles both to 'Plant and pasted.

plates.

The advantages of incorporating with the active material of the plate, a porous inert substance for the purpose of keeping open the pores of the plate during continued service. is well understood. Among the many advantages are the following: The spongy portions are prevented from consolidating into a mass more dense than is favorable to the free circulation of the electrolyte. This tendency to condense is seen particularly as the plates become old and any arrangement for retaining the original characteristics of the plates, also helps maintain the life and efliciency of the battery. Also the plates are further mecl'ianically improved, as they are better able to withstand the disintegrating tendencies due to repeatedcontraction and expansion, particularly in pasted plates. In the methods previously adopted to secure the above advantages, two steps are usually First, the plate is immersed in a solution of soluble salt or a soluble body and the saturated plate is then off. Another method is to soak the formed plate in a solution of sugar, whereby finely divided organic material is deposited in the plate, which is afterward baked to carbonize the sugar. The carbonized material, being unaffected by the electrolyte, has the effect of increasing the useful life of the plate.

Specification of Letters Patent.

Patented Dec. Mi, i915.

Application filed March 8, 1910. Serial No. 548,027.

These processes are known as permanizlng processes. in that they tend to increase the useful life of the plate, and hence tend to render the same more permanent. I

The present invention aims to secure the advantages of the priorprocesses by using a single step instead of two, thereby improving and cheapening the method.

The per-sulfates of the alkaline earths have the power of oxidizing certain metals, par-- ticularly sponge lead, and by the reaction, the per-sulfate salt is decomposed, forming lead oxid and normal sulfate. This reaction applies particularly to the persulfates of barium and calcium, the normal sulfates of which are practically insoluble and therefore well adapted when diffused throughout the active ma ss.of a battery plate, to lengthen the useful life thereof by acting as a socalled permanizer.

In carrying out my process I immerse the formed battery plate in a solution of a single persulfatc salt, and thereby obtain the reaction explained above. The insoluble normal sulfate is uniformly diffused throughout the active mass, and preserves the porous spongy clmracteristics necessary for the free diffusion of the electrolyte. During the drying of the electrode, before treatment with the per-sulfate, more or less of the sponge lead is converted to the leadoxid PbO. The reaction of the per-sulfate on the sponge lead'is probably as indicated in the following formula:

thus oxidizing the lead to a normal oxid, PM). This in turn is oxidized by an excess of the alkaline persulfate to lead peroxid, the reaction for which is probably represented by the following formula As stated above, the persulfates of the alkaline earths are particularly well adapted for the foregoing reaction, but I do not limit myself to them but intend to include any substance or compound, capable of acting on the plates to deposit therein an inert substance in a single step, and coming within the scope of the appended claims.

Having thus described my invention, what I'claim as new and desire to secure by Letters Patent of the United States is:

l. The process of treating negative battery plate to the action of a salt solution having. the properties of oxidizing the lead of theplate and at the same time splitting out a 4:. A process of tery plate which consists in subjecting the formed plate to the action of a solution Copies of this patent may be obtained for which has the property of re-acting with the lead of the plate to form an insoluble inert sed throughfected by charging and discharging the battery which remains diffused throughout the plate.

In witness whereof, I haye hereunto subscribed my name in the presence of two witf I-nesses. insoluble compound which remains difi'usedfthroughout the plate.

permanizing a lead bat- I CAMPBELL o. CARPENTER.

Witnesses:

HENRY l/V. BINDERNAN, C. D. TALLMAGE.

five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

